Allow parallelism in COPY (query) TO ...;

anarazel · anarazel · commit 34aebcf42a70 · 2017-06-02T19:11:15.000-07:00
Previously this was not allowed, as copy.c didn't set the CURSOR_OPT_PARALLEL_OK flag when planning the query. Set it. While the lack of parallel query for COPY isn't strictly speaking a bug, it does prevent parallelism from being used in a facility commonly used to run long running queries. Thus backpatch to 9.6. Author: Andres Freund Discussion: https://postgr.es/m/20170531231958.ihanapplorptykzm@alap3.anarazel.de Backpatch: 9.6, where parallelism was introduced.
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
@@ -1527,7 +1527,7 @@ BeginCopy(ParseState *pstate,
 		}
 
 		/* plan the query */
-		plan = pg_plan_query(query, 0, NULL);
+		plan = pg_plan_query(query, CURSOR_OPT_PARALLEL_OK, NULL);
 
 		/*
 		 * With row level security and a user using "COPY relation TO", we

Original file line number	Diff line number	Diff line change
`@@ -1527,7 +1527,7 @@ BeginCopy(ParseState *pstate,`
`1527`	`1527`	`}`
`1528`	`1528`
`1529`	`1529`	`/* plan the query */`
`1530`		`- plan = pg_plan_query(query, 0, NULL);`
	`1530`	`+ plan = pg_plan_query(query, CURSOR_OPT_PARALLEL_OK, NULL);`
`1531`	`1531`
`1532`	`1532`	`/*`
`1533`	`1533`	`* With row level security and a user using "COPY relation TO", we`